Table 1.

Examples of current and future human health vulnerability and adaptation.

Definition	Current	Future
Vulnerability: the degree to which individuals and systems are susceptible to or unable to cope with the adverse effects of climate change.	Populations living in areas on the fringe of the current distribution of malaria are at risk for epidemics if the range of the Anopheles vector changes.	Whether these populations might be vulnerable in the future depends, in part, on the implementation of timely and effective prevention activities.
Adaptation baseline: the adaptation measures and actions in place in a region or community to reduce the burden of a particular health outcome.	The exposure–response relationship is influenced by the current prevention measures aimed at reducing the burden of a disease. For example, the number of older adults adversely affected by a heat event depends on the numbers who have access to and who use air conditioning during a heat event.	Increasing access to and use of air conditioning will reduce the percentage of older adults who could be adversely affected by future heat events.
Coping capacity: the adaptation options that could be implemented now. Specific adaptation plans arise from a region or community’s coping capacity.	Several cities in middle-latitude countries have the level of material resources, effective institutions, and quality of public health infrastructure to establish and maintain early warning systems for heat events. Until implemented, these systems are within a city’s coping capacity.	Over time, adaptation options can move from being possible to being implemented (i.e., being part of the adaptation baseline). For example, universal access to adequate quantities of safe water is not yet possible, although significant progress has been made.
Adaptive capacity: the general ability of institutions, systems, and individuals to adjust to potential harm, to take advantage of opportunities, or to cope with the consequences of climate variability and change.	Adaptive capacity is the theoretical ability of a region or community to respond to the threats and opportunities presented by climate change. It encompasses both coping capacity and the options that have the potential to expand future coping capacity.	Over time, it is hoped that regions and communities will increase their resilience to what the future climate brings.

Adapted from Kovats et al. (2003b).